H. Woo and T. D. Tilley, J. Am. Chem. Soc., vol. 111 pp. 8043-8044 (1989) describe the dehydrocondensation of silanes of the type RSiH.sub.3 with dimethylbis(pentamethylcyclopentadienyl) compounds of zirconium and hafnium to form polysilanes. Other isoluble hafnium and zirconium compounds which were postulated to be intermediates in the dehydrocondensation reaction were also shown to be active in forming the polysilanes.
French Patent No. 2,565,234 reports the dehydrocondensation of silanes of the formula RSiH.sub.3 with similar (to those above) compounds of titanium and zirconium. The products of the reactions are polysilanes. J. F. Harrod and coworkers, in a series of papers, expanded on this reaction: J. Organometal. Chem., vol. 279, pp. C11-13 (1985); J. Am. Chem. Soc., vol. 108, pp. 4059-4066 (1986); Organometallics, vol. 6, pp. 1381-1387 (1987); Polym. Prepr. vol. 28 pp. 403-404 (1987); Can. J. Chem., vol. 64, pp. 1677-1679 (1986); and Can. J. Chem., vol. 65 pp. 1804-1809 (1987). These papers disclose reactions to form the polysilanes and the structure of the polysilanes so produced. The polysilanes are described as being of relatively low molecular weight, and containing up to about 20 silicon atoms. W. H. Campbell, et. al., Organometallics, vol. 8 pp. 2615-2618 (1989) further investigated the products of the reaction of bis (.eta..sup.5 -cyclopentadienyl)dimethylzirconium with n-butylsilane. Cyclic and linear polysilanes containing up to 8 silicon atoms were obtained.
European Patent Application No. 314,327 describes the polymerization of compounds of the formula R.sup.1 R.sup.2 SiH.sub.2, where R.sup.1 is hydrogen or hydrocarbon and R.sup.2 is hydrocarbon, using an organometallic complex of nickel, cobalt, ruthenium, palladium or iridium as a catalyst.
In all of the above references no mention is made of the use of scandium, yttrium or rare earth metal compounds to catalyze the dehydrocondensation of silanes to form polysilanes.
Hydrosilation of olefins, particularly alphaolefins, is a well known reaction. Such reactions are known to be catalyzed by a variety of agents, including certain transition metals, see for example E. Y. Lukevits and M. G. Voronkov, Organic Insertion Reactions of Group IV Elements, Consultants Bureau, New York, 1966.
M. G. Voronkov and S. P. Sushchinskaya, Zh. Obshch. Khim., vol. 56, pp. 627-32 (1986) describe the use of LaCl.sub.3, CeCl.sub.3, NdCl.sub.3, EuCl.sub.3, DyCl.sub.3, ErCl.sub.3 and LuCl.sub.3 as additives for the H.sub.2 PtCl.sub.6 catalyzed hydrosilation of phenylacetylene with triethylsilane. Several of these metal halides increased the yield and/or changed the ratio of isomers obtained when compared with the reaction using H2PtC16 alone. No reactions were run without H.sub.2 PtCl.sub.6, a known hydrosilation catalyst.
It is the object of this invention to provide processes for the hydrosilation of alpha-olefins, and the dehydrocondensation of silanes of the type R.sup.1 R.sub.8 SiH.sub.2 to form polysilanes. It is a further object of this invention to provide novel catalysts for use in these processes.